Norwich — Kelly Middle School, damaged by a small fire and extensive water damage early Monday, will reopen today, but more than 200 students will be relocated to makeshift classrooms in staff rooms, the school community room and other locations until the two damaged wings can reopen.

As of late Monday, no cost estimates were available for the damage, although the school system’s insurance deductible is $10,000. Insurance company personnel were on the scene Monday and will return Wednesday to assess damage costs, Superintendent Abby Dolliver said.

The fire started at 2:26 a.m., when an older computer in the new second-floor science lab smoldered and burned. Two overhead sprinklers were triggered and sent water cascading onto the floor, into the hallway, down the stairway and through ceilings. Firefighters had to break the glass in the locked classroom door to enter the room.

Fire damage was contained to the computer, but water damage was much more extensive. About 30 classrooms had some water in them. In the dozen most damaged classrooms, ceiling tiles became soaked and collapsed onto desks and floors, and water seeped through walls. In the science classroom directly beneath the classroom where the fire started, water was about a foot deep before crews used pumps and later floor scrapers to direct the water to hallway floor drains.

Connecticut Mastery Tests were scheduled to begin for all students today, but Curriculum Director Joseph Stefon said writing tests for seventh-graders were soaked and must be replaced.

School officials expect to receive replacement tests today and state Department of Education officials gave permission for seventh-graders to take the test Wednesday.

One large preschool class at Kelly also will be affected by the need to relocate classes. School officials had planned to move most preschool classes throughout the city to the recently vacated Bishop School starting next school year. But now the Kelly class will move to Bishop starting Wednesday.

Board of Education Chairwoman Yvette Jacaruso thanked emergency responders and cleanup crews, who worked Monday to get school ready to reopen.

A $40.2 million expansion and renovation was completed a year ago at Kelly. The fire and water damage occurred mostly in the new two-story science classroom wing. Jacaruso said the new sprinkler system worked as planned, dousing the fire quickly and limiting fire and smoke damage.

But the sprinklers must be turned off manually by fire officials once they are assured the fire has been extinguished. School Business Administrator Athena Nagel estimated more than 6,000 gallons of water sprayed from the sprinklers.

Crews from G. Schnip Construction, which built the expansion, electrician DEF Wiring Services, Standard Sprinkler Corp. and Servicemaster were at the school Monday assessing damage and starting repairs.

Taftville Fire Chief Timothy Jencks said firefighters responded to the school for a fire alarm call. When they looked at the alarm panel, they noticed that numerous smoke detectors had been set off.

As fire crews investigated, they discovered smoke and water in the hallways in the science wing on the upper floor. Jencks said water was seeping down the hallways and cascading down the stairs onto the first floor as firefighters laid out salvage covers to protect computers on the first floor. Jencks said power to that part of the building had to be shut off.

Nagel said the computer was turned off, and was plugged into a surge protector — "like all the others." The city fire marshal's office is investigating the cause of the fire.

c.bessette@theday.comi.larraneta@theday.com

A melted computer, at left end of counter, sits in the classroom where it caught fire in the early hours of Monday morning March 4, 2013 at Kelly Middle School in Norwich. Damage to the 7th-8th grade wing of the school was extensive enough to force the closing of the building.

Sodden ceiling tiles cover a lab table in the classroom underneath the classroom where a fire in a computer at Kelly Middle School set-off the school's sprinklers in the early hours of Monday morning March 4, 2013. Damage to the 7th-8th grade wing of the school was extensive enough to force the closing of the building.

A crew from Servicemaster Juan Rosario and Muhammed Yakubu clean-up after a fire in a computer set-off the sprinklers at Kelly Middle School in the early hours of Monday morning March 4, 2013. Damage to the 7th-8th grade wing of the school was extensive enough to force the closing of the building.